Fremco cable gasket 103-10240 is the 4.5 mm gasket for MiniFlow fiber blowers, supplied in packs of six and priced per each. It seals around very small fiber optic cable at the blower inlet, holding air pressure behind the cable so the jetting force is not lost to blow-by. At 4.5 mm the tolerance window is narrow, and using the exact gasket size is the difference between a full-length shot and a stall. A frequently replaced consumable on FTTH drop and microduct crews. Millennium part #612265.